Shock absorber



April 8, 1941.` N. E; Rom-SON SHOCK ABSORBER Filed om. 2a, 1939 /7/ 7/Af/Af //////7///7/-7/4// inmortalidad flipt. 1941 SHOCK ABSORBER Neal E.Routson, Lakewood, Ohio, assignor to Lucien R. Gruss, Cleveland, OhioApplication October 28, 1939, Serial No. 301,820 A (Cl. 2mm-34) 4Claims.

This invention relates to lluid shock absorbers, and more particularlyto an improved shock absorber of, this type which is well suited for useon various kinds of motor vehicles for retarding or dampening movementbetween two relatively movable parts, such as the frame and axle of thevehicle.

an object of my invention is to provide an improved fluid shock absorberof the type having a movable piston for causing a discharge of fluidthrough a restricted passage or opening and in which the shock absorbingaction yresultlnc irom such restricted discharge of iluid issupplemented by the action'of a resiliently yieldable means embodied inthe piston actuating means.

Another object of my invention is to provide an improved fluid shockabsorber of thetype having a movable piston for subjectingthe-'resistance iluid to pressure and in which such piston. is hollowand houses a resilient means by which an actuating member is connectedwith the piston and which functions as an auxiliary shoclt absorbingmeans.

il. further object of my invention is to provide an improved vehicleshock. absorber having a piston operable to force fluid through a restricted valve-controlled passage for developing a main shock absorbingaction between relatively movable vehicle parts and having pistonactuatlng means embodying a resilientlylyieldable aux lliary shockabsorbing means upon which the vehicle body substantially floats.

Other objects and advantages of my invention will be apparent from thefollowing description when taken in conjunction with the accompanyinasheet of drawings in which:

lila. l. is a longitudinal sectional view taken through a shock absorberembodying my inven tion;

lilla. la is a transverse sectional view taken through Athe device asindicated by line 2-2 of lt'llg. l: and

2tlg. a is another transverse sectional .view taken through the shock:absorber on line 3-3 ci lllgl. l

lin the embodiment of my invention illustrated` ln the drawing I show ashock absorber or the direct-acting tubular type, and although myinvention is hereinafter described by making de-` tailed reference tothe construction and operation or a shoclt absorber oi' this particulartype, lt will be understood, however, that the invention may be embodiedin various other kinds of shock absorbers and similar devices comingwithin the scope of the appended claims.

.The shock absorber shown :In the drawing in cludes an elongated tubularcylinder barrel Ill providing a working chamber or cylinder II, and apiston I2 slidable in the cylinder barrel and .adapted to bereclprocated therein by an operating member in the form of an actuatingrod I3. A tubular reservoir cylinder or barrel I4 coaxlally surroundsthe cylinder barrel I Il so as to provide therebetween a reservoirchamber I5. The ends of the shock absorber housing or cylln derareformed by the plugs or cover members IB and II. The plug IE may beconnected with the outer or upper end of the reservoir barrel I4 Vbybeing screwed thereinto and is provided with an opening or bearing I8 inwhich the actuating rod I3 is slidable. The plug I8 is also prof videdwith an annular seat I8 which is engaged by and locates the outer endo1' the cylinder barrel I0. A washer or ring 20 may be providedbetweenthe outer end of the cylinder barrel I0 and the reservoir barrelI4 and bears against a packing ring or gasket 2| for forming an annularfluid seal between the cylinder and reservoir chambers.

The'plug or cover member Il may be welded or otherwise connected to theinner or lower end of the reservoir barrel I4 and may have a connectingportion thereon, such as the eye 2l. by which this end of the device maybe connected with the axle or other movable part to be retarded. Aninner cover member 24 may be located between the plug I1 and the inneror lower end of the cylinder barrel ID. This inner cover member servesto center and locate the lower end of the cylinder barrel I0 and enables the latter to be clamped in position be` tween the plugs IB and I1 when the parte are assembled and the plug Il is welded or otherwiseconnected to the reservoir barrel I4. The plug I'I may also be providedwith a filling opening which communicates with the reservoir Ill and maybe closed by the screw plug 25.

Resistance fluid, such as oil or other appro- `prate liquid,substantially `illls the working l `chamber extending between the pistonI2 and the inner cover 24 and partially illls the reservoir chamber Il.The space in the reservoir cham ber above vthe level of the liquidcontains air which `is compressed when the level oi' liquid rises in thereservoir, as will be explained more fully hereinafter.

For developing a shock absorbing resistance in ing 2l adjacent the lowerend of the cylinder barrel which extends between the working chamber iland the reservoir i5, but is normally closed by a check valve whichopens outwardly when suilicient pressure is developed in the workingchamber. This check valve may be in the form oi a ball 2% seatingagainst the outer end of the restricted passage 2T and yieldingly heldthereagainst by the compression spring 29. A bushing Sii mounted in anopening of the reservoir barrel ifi forms a guide for the inner end ofthe spring and also serves as a connecting means for the spring housingSi. The force tending to hold the ball 2B seated can be varied oradjusted to thereby vary the shock absorbing resistance which is to bedeveloped in the device and this ervoir chamber I5 into the workingchamber il,

I provide the inner cover 24 with relatively large return passages 32and 33 and a check valve which normally closes the passage 33 but isadapted to open into the working chamber il. This check valve may be inthe form of a valve disk 34 having a stem or pin 35 extending throughthe inner cover 24 and may be normally held seated against the innercover by the compression spring 36.

The piston I2 may comprise an elongated tubular body izo which isslidable in the cylinder barrel i@ and is provided with end walls 3S andSie. The end wall 3S may carry a cup-shaped packing s@ formed of leatheror other flexible material. The end wall 3S has an opening 4I throughwhich the actuating rod I3 freely extends. This wall also forms a stopwhich is adapted to be engaged by an abutment, in this instance in theform of a disk 42, carried by the actuating rod during outward movementof the latter.

For developing an auxiliary shock absorbing action in myimproved device,I may provide a resiliently yieldable operating connection between therod I3 and the piston I2. To this end I provide a resiliently yieldablemeans in or on the hollow piston I2, in this instance in the form oi acoiled compression spring 43, which is adapted to yield when a thrust orload is applied to the rod I3 in a direction to cause inward movement ofthe piston. The spring 43 may be housed in thchollow piston with itsends seating, respectively, against the end wall 38 of the piston andthe abutment disk 42 of the actuating rod.

The resilient connection thus provided between the actuating rod i3 andthe piston I2 serves as a cushioning and shock absorbing means uponwhich the weight of the vehicle, and of the passengers or load carriedthereby is supported in a more or less floating manner. 1in thisconnection I wish to explain that the spring-loaded valve 28 maintainsthe restricted passage 2 closed until an excessive or predeterminedpressure occurs in `the working chamber ti and, therefore, the initialthrust applied to the piston by the actuating rod I3 is taken up byyielding of the spring 43. With the characteristic of the springs 43 and29, and the area oi the restricted passage 2l and other parts of thedevice properly proportioned, the weight oi' the vehicle and its loadwill more or less float on the spring 43 and the body of liquidcontained in the working chamber II, but if a sudden or excessive thrustis applied to the actuating rod lil, as when the vehicle wheelencounters a bump, it will be transmitted through the spring 43 to thepiston causing inward movement thereof and this will cause some of theresistance iluid to be discharged through the restricted passage 2lthereby resulting in a main shock absorbing resistance being developedin the device. During the compression of the spring 3 the abutment disk42 moves into the piston away from the end Wall 39 thereof and uponoutward movement of the actuating rod i3, such as during lightening ofthe load carried by the vehicle or during rebound movement, the abutmentdisk 42 moves toward and engages the end wall 39 whereupon a positiveretracting connection is formed between the actuating rod and piston.

. To render my improved shock absorber double acting, I may provide thecylinder barrel I0 with a restricted discharge opening or passage 45adjacent its upper end. This restricted opening may be formed by theopening in the end or mouth of the tube 4G, or may be formed by thespace intervening between the mouth of this tube and the adjacentportion of the plug I6. The tube 46 thus provides an open but restrictedpassage which connects the upper end of the working chamber or cylinderwith the reservoir I5.

On upward or outward movement of the piston l2, particularly a suddenoutward movement such as would occur during rebound, any body of liquidcontained in the cylinder above the piston will be subjected to pressureand will be forced back into the reservoir through the restrictedpassage 45 thereby developing additional shock absorbing resistance in`the device. The body of liquid which may exist or occur in the cylinderabove the piston I2 may be liquid which has leaked between the pistonand cylinder or it may be liquid which has been forced upward throughthe tube 46 during the inward or compression stroke of the piston.

The space in the reservoir chamber I5 above the level of thev liquidcontains air, as above stated, and when fluid is forced into thereservoir this air is compressed more or less and on the outward strokeof the piston tends to accelerate the return ow of fluid past the checkvalve 34. The air pressure thus built up in the reservoir also causesfluid to be forced up through the tube 46 into the cylinder above thepiston so as to provide uid in the upper cylinder chamber for retardingrebound movement of the piston.

It will be noted that the tube 46 is of substantial length and that itslower end extends well below the level of liquid in the reservoir and toa point adjacent the valve-controlled restricted passage 21. This isdesirable because it permits liquid to be forced up through the tube 43into the upper end of the cylinder during the compression stroke of thepiston, as above explained, and also tends to prevent agitation of thereservoir liquid and the formation of an air and oil emulsion whenliquid is discharged back into the reservoir from the upper end of thecylinder through the restriction 45.

The escape of liquid from the device around the actuating rod I3 may beprevented by providing a suitable packing 48 in the plug I6 outwardly ofthe bearing I8. Dust and other foreign matter may be excluded from thevicinity of the actuating rod and the packing il! by means of a tubulardust shield 49 which telescopes the resnum may be discharged into thereservoir by ervoir barrel I 4 and is connected with the end of theactuating rod by means of the fitting 50 by which the actuating rod isadapted to be connected with the vehicle frame or other movable part tobe retarded.

From the foregoing description and the accompanying drawing it will nowbe readily understood that I have provided an improved shock absorber ofthe iiuid type which is well suited for use on various kinds of motorvehicles and which is so constructed that the weight of the vehicle andthe load carried thereby will be supported in a more or less iioatingmanner by the shock absorber. It will also be seen that this floating ofthe vehicle and its load is brought about by the use of a normallyclosed restricted fluid passage and a resiliently yieldable operatingconnection between the actuating rod and piston. This yieldableoperatingconnection between the actuating rod and piston not only servesto float the weight and load of the vehicle, but also serves as anauxiliary shock absorbing means which cush` lons and absorbs therelatively lighter shocks and vibrations.4 It will also be seen that myimproved shock absorber is a double-acting device and that the moresudden and severe shocks-will be absorbed by the forced discharge ofliquid through the restricted openings of the device.

While I have illustrated and described my iniproved shock absorber in amore or less detailed der, a reservoir. resistance fluid in the cylinderand reservoir, a piston operable in the cylinder .tor subjecting theiiuid to pressure, said cylinder having restrictions adjacent itsrespective ends the piston, an actuating rod extending into the cylinderand hollow piston, an abutment on said rod engageable with the piston toform a positive connection therebetween for movement of the pistontoward one of said restrictions, and a coiled spring in the piston foryieldingly transtlhrough which fiuidmay be discharged into the ,Y

reservoir by the piston, an actuating member extending into thecylinder, and means providing a positive connection between the pistonand ac tuating member for movement of the piston to ward one of saidrestrictions and a yieldable connection therebetween for movement of thepisand reservoir, an elongated hollow piston operable :in the cylinder,said cylinder having restric tions adjacent its respective ends throughwhich mitting" thrust between said rod and piston during movement oi'the piston toward the other restrction.

3. In a hydraulic shock absorber, an elongated cylinder havingrestricted openings adjacent its respective ends, a reservoirsurrounding the cylinder, liquid in the cylinder and reservoir, aspring-loaded valve normally closing the restricted opening adjacent theinner end of the cylinder, a piston operable in said cylinder andadapted to cause a discharge of liquid past said springi loaded valve onone stroke and a discharge through the other restricted opening on theopposite stroke, means connected with the piston for actuating the same,and a conduit having one end arranged to receive the discharge from saidother restricted opening and its other end submerged in the reservoirliquid, said conduit providing an open return passage which terminatesin the reservoir adjacent said spring-loaded valve.

4. In a double acting tubular shock absorber, a reservoir, an elongatedcylinder having a re-u stricted discharge opening connecting the innerend thereof with said reservoir and a restricted passage leading intothe reservoir from adjacent the outer end of the cylinder, a valve forsaid opening, a spring acting on said valve to seat the same butpermitting opening thereof toward the reservoir, a hollow pistonoperable in the cylinder and adapted upon movement toward the inner endthereof to subject the liquid therein to pressure for causing adischarge of liquid past said valve into the reservoir and upon moverment toward the outer end to cause a discharge of duid through saidrestricted passage into the reservoir, an actuating rod extending intothe cylinder and hollow piston and having an abutment engageable with' aportion oi? the piston to provide a positive connection for outwardmovement of the piston, a spring in said hollow piston adapted to yieldduring application of thrust tending to move the piston toward saidrestricted opening, and adjustable means accessible from the outside ofsaid cylinder for vary ing the effect of the rst mentioned spring onsaid valve, said restricted passage opening into the reservoir at apoint adjacent said valve.

NEAL E. ROUTSON. i

